Algebra
posted by Christina .
Solve by elimination method.
7r3s=14
3r+7s=64
Could never figure out the elimination method. Would love some help with this one. Thanks

21r  9s = 42
(I multiplied the first eq. by 3)
21r + 49s = 448
(I multiplied the second equation by 7)
58s = 406
(I subtracted the third equation from the fourth, to eliminate r.)
The remaining steps are easy.
s = 7
7r 21 = 14
r = 5